Pyrrolo{8 1,2,3-de{9 quinoxalin-2-(3H)-ones and related compounds

ABSTRACT

This invention concerns pyrrolo (1,2,3-de)quinoxalin-2(3H)-ones and related compounds which are pharmacologically active as central nervous system depressants.

Sellstedt et al.

PYRROLO[1,2,3-DE]QUINOXALIN-2- (SID-ONES AND RELATED COMPOUNDS Inventors: John H. Sellstedt, Pottstown; Milton Wolf, West Chester, both of Pa.

Assignee: American Home Products Corporation, New York, NY.

Filed: Jan. 25, 1974 Appl. No.: 436,570

Related US. Application Data US. Cl 260/250 Q; 424/248 Int. Cl C07d 57/24 June 24, 1975 [58] Field of Search 260/250 BC, 250 Q [56] References Cited FOREIGN PATENTS OR APPLICATIONS 237,153 2/1969 U.S.S.R. 260/250 BC 256,776 11/1970 U.S.S.R 260/250 Q Primary Examiner-Alton D. Rollins Attorney, Agent, or Firm-.loseph Martin Weigman 5 7] ABSTRACT This invention concerns pyrrolo [1,2,3-de1quinoxalin- 2(3l-l)-ones and related compounds which are pharrnacologically active as central nervous system depressants.

1 Claim, No Drawings 1 PYRROLOO ,2,3-DE)QUINOXALIN-2-(3H)-ONES AND RELATED COMPOUNDS This application is a division of application Ser. No. 252,990 filed May 15, 1972, which was issued on May 28, 1974 as U.S. Pat. No. 3,813,392 which was in turn a division of application Ser. No. 831,723 filed June 9, 1969, now abandoned.

This invention relates to new and novel quinoxalines. More particularly it relates to pyrrolo[ 1,2,3-delquinoxalin- 2(3H)-ones and related compounds which in standard and accepted biological tests have demonstrated usefulness as central nervous systemdepressants.

The new and useful compounds of the present invention are exemplified by those having the formula:

wherein R and R are selected from the group consisting of hydrogen, nitro, amino, carboxy, cyano, carbamy], sulfamyl, trifluoromethyl, halogen, lower alkyl, lower alkoxy, lower alkylthio, carb(lower)alkoxy, lower alkylsulfonyl, carboxy (lower)alkyl, lower alkanoylamino, di(lower)alkylamino, phenyl, halophenyl, lower alkylphenyl, lower alkoxyphenyl, phen(- lower) alkyl, phen(lower)alkoxy, morpholino, pyridyl,

ylene containing from about 5 to about 12 carbon atoms, l-(lower)alkyl-l-cyclohexen-l,2-ylene and 3,4-dihydro-l,2-naphthylene; and R,-, is selected from the group consisting of hydrogen, lower alkyl, cyano(- lower)alkyl, phen(lower)alkyl, morpholino(lower)alkyl, lower alkylamino(lower)alkyl, di(lower)alkylamino(lower)alkyl, N-(lower)alkyl-N- (lower)alkanoylamino(lower)alkyl aziridinyl lower- )alkyl, azetidinyl(lower)alkyl, azolidinyl(lower)alkyl, azinyl(lower)alkyl, azepinyl(lower)alkyl, r r (lower)alkyl-piperazinzl(lower)alkyl, 1- phenylpiperazinylflower)alkyl, 1- halophenylpiperazinyl( lower)alkyl and 1- phen(lower)alkyl-piperazinyl(lower)alkyl. As employed herein the terms lower alkyl, lower alkoxy", lower alkanoyl and the like are meant to include both branched and straight chain hydrocarbon groups having from one to about seven carbon atoms. The term halogen? as used herein is meant to include chlorine, bromine, iodine and fluorine. Typical examples of these compounds are: 7,8,9,lO-tetrahydro-8-methyl- 1H-pyrido[3,4: 4,5 ]pyrrolo[ l ,2,3-de]quinoxalin- 2(3H)-one; 8,9-dihydro-1H,7H- benzo[3,4]cyclohepta[1,2:4,5]pyrrolo[l,2,3-de]- quinoxalin-2( 3H)-one; 8,9,10-1 l-tetrahydro- 1 H,7H- cyclohepta[4,5 ]pyrrolo 1,2,3-de1quinoxalin- 2(3H)-one; 7,8,9,10,l1,12-hexahydro-1H- cycloocta[4,5 ]pyrrolo[ 1 ,2,3-de]quinoxalin- 2( 3H)-one; 8-tert-butyl-7,8,9, lO-tetrahydrol H- pyrazino[3,2,1-jk]carbazol-2(3H)-one; 2,3-dihydro-2- oxo-5-phenyl-1H-pyrrolo[ 1,2,3- delquinoxaline-6-acetic acid; 8,9,10, l l-tetrahydro-3- methyl- 1 H,7H-cyclohepta[4,5 ]pyrrolo[ l,2,3-de]- quinoxalin-2(3H)-one; 3-(2-dirnethylaminoethyl)- 89,10, 1 l-tetrahydro- 1 H,7H-cyclohepta [4,5 ]pyrrolo[- 1,2,3-de]quinoxalin-2(3H)-one; 2,3,89,10,1 hexahydro-2-oxo-l H,7H- cyclohepta[4,5]pyrrolo[1,2,3-de1quinoxaline-3- acetonitrile; 8,9, 10,1 l-tetrahydro-3-phenethyll l-l,7l-l= cyc1ohepta[4,5 ]pyrrolo[ 1 ,2,3-de]quinoxalin- 2( 3H)-one; 6-methyl l 2-dimethylaminoethyl-5- phenyll H-pyrrolo[ l ,2,3-de]quinoxalin-2( 3H )-one; and l-( 3-dimethylaminopropyl)-5-methyl-6-phenyllH-pyrrolo[ 1,2,3-de]quinoxalin-2(3H)-one.

The new and novel compounds of the present invention may be prepared by the process which is exemplified by the following reaction scheme:

wherein R R R,-, R and R are defined as above and X is a halogen. The reduction-cyclization reaction is effected by contacting a l-nitroso-3,4-dihydroquinoxalin-2( 1I-I)-one (I) with zinc dust in acetic acid for about one-half hour at about ambient temperatures. Thereafter, the reduced mixture is contacted with an appropriate ketone (II) at about reflux temperatures for a period of up to about 30 minutes to afford an appropriate l-unsubstituted product (III). Preferably this reaction is conducted in glacial acetic acid. When the reductioncyclization reaction is complete, the l-unsubstituted product (III) is separated by conventional recovery procedures e.g. filter the reaction mixture, wash the cake with acetic acid and a liquid alkanol, and crystallize the l-unsubstituted product (III) from a suitable solvent, such as, dimethylformamide or dimethylacetamide.

The alkylation reaction is effected by admixing the above-prepared l-unsubstituted product (III) with hexane washed 50 percent sodium hydride, in an anhydrous, reaction-inert solvent, e.g. dimethylformamide. To this mixture, there is added a solution of an appropriate halide (IV) in an anhydrous, reaction-inert solvent, e.g. dimethylformamide at a temperature range from about 70C. to about 90C. for a period of up to about 2 hours. When the alkylation is complete, the resulting l-substituted product (V) is recovered by standard techniques. For example, the solvent is evaporated to afford a residue which is purified and then crystallized from a suitable solvent, e.g. an alkanol.

The l-nitroso-3,4-dihydroquinoxalin-2(1H)-ones (I) employed as starting materials in the above-described process are prepared by the procedure of Perkin, W.I-l. and Riley, G.C. in J. Chem. Soc., 2399 (1923). The ketones (II) and halides (IV) employed in these reactions are commercially available or are easily prepared by processes well known in the chemical art.

The new and novel l-unsubstituted (III) and lsubstituted (V) products of this invention possess valuable pharmacological activity. In particular, these compounds in standard pharmacological procedures demonstrate nervous system activity and are useful as depressants. Because of this property they are of particular importance in producing a calming effect in animals.

In the pharmacological evaluation of the central nervous system depressant compounds of this invention the in vivo effects of the compound of this invention are tested as follows: The compound is administered orally and intraperitoneally to three mice (14 to 24 grams) at each of the following doses: 400, 127, 40 and 12.7 mg./kg. The animals are watched for a minimum of two hours during which time signs of general stimulation (i.e., increased spontaneous motor activity, byperactivity on tactile stimulation, twitching), general depression (i.e., decreased spontaneous motor activity, decreased respiration) and autonomic activity (i.e., miosis, mydriasis, diarrhea) are noted. The animals are tested for changes in reflexes (i.e. flexor, extensor) and are rated by use of a pole climb and inclined screen for the presence of sedation-ataxia. The Eddy Hot-Plate Method [Nathan B. Eddy and Dorothy Leimbach, J. Pharmacol. Exper. Therap. 107, 385 (1953)]is used to test for analgesia. The experiment is terminated by subjecting each animal to a maximal electroshock to test for anti-convulsant activity.

The compounds of this invention in the above test procedure induce decreased motor activity and debody weight:

creased respiration Whe ..Jm.:1istercd at a dosage range of 12.7 to 400 mg/kg. There were no deaths in the test animals at the highest dose used. 400 mg./kg. orally and intraperitoneally.

The l-unsubstituted products (III) of the present invention are also useful intermediates in the preparation of the corresponding l-substituted products (V) hereof. Further, when tested by the procedure set forth in the Cancer Chemotherapy Raports Number 25, the following l-substituted products (V) of the present invention have demonstrated activity as anti-tumor agents when administered to rats at an intraperitoneal dosage range from about 62.5 to about 175 mg./kilo of l( 3-diemthylaminopropyl)-6-ethyl-5- phenyll I-I-pyrrolo[ 1,2,3-de ]quinoxaline-2( 3I-I)-one; 1-( 3-dimethylamino-2-methylpropyl )-6-ethyl-5-phenyl-lH-pyrrolo [l,2,3-de]quinoxalin-2(3l-I)-one; (Zdimethylaminoethyl-6-ethyl-S-phenyl-1H- pyrrolol1,2,3-de]quinoxalin-2(3l-I)-one; 1-(2- diethylaminoethyl)-6-ethyl-5-phenyl-1H- pyrrolo[ l,2,3-de]-quinoxalin-2( 3I-I)-one; 6-ethyl-5- phenyl-1[3-( 1-pyrrolidinyl)propyl]- l l-l-pyrrolo[ 1,2,3- de ]quinoxalin-2( 3H )-one; I-( 3- dimethylaminopropyl)-5-(p-methoxyphenyl)-6- methyl-lI-I-pyrrolo[ 1,2,3-de] quinoxalin-2(3H)-one; 5-(p-benzyloxyphenyl)- 1-(3-dimethy1aminopropyl)-6- methyl-lI-I-pyrrolo[1,2,3-de]quinoxa1in-2(3I-I)-one; 1-( 3-dimethylaminopropyl )-5-(p-hydroxyphenyl)-6- methyl-lH-pyrrolo[1,2,3-de]quinoxaline-2(3I-I)-one; 6-methyl-1-(2-dimethylaminoethyl-5-phenyl-1H- pyrrolo[ l ,2,3-de]quinoxalin-2( 3I-I)-one; 3-(2- diemthylaminoethyl)-7,8,9,10, 1 1,12-hexahydro-lI-I- cycloocta[4,5]pyrrolo[1,2,3-de1quinoxalin- 2(3H)-one; S-benzyl-1-(2-dimethylaminoethyl)-6- phenyll I-I-pyrrolo[ 1 ,2,3-de]quinoxalin-2( 3H)-one; and 1-( 2-dimethylaminoethyl)-6-ethyl-5-pheny1-l H- pyrrolo[l,2,3-de]quinoxalin-2(3H)-one. Still further, some of the l-substituted products (V) of the present invention have also demonstrated immunosuppressive activity by their ability to inhibit experimentally induced allergic encephalomyelitis in rats when administered at an intraperitoneal dosage range of about to about 200 mg./kilo of body weight. This immunosuppressive activity was tested by procedures of Brandrise, M.W. Science :186, 1963 and Levine et al Proc, Soc. 1 14:220, 1963. The compounds which have demonstrated this activity are: 1-(3-dimethylaminopropyl)- 6-ethyl-5-phenyl-lI-I-pyrrolo[ 1,2,3-de1quinoxalin- 2( 3H )-one; l-( Z-dimethylaminoethyl)-6-ethyl-5- phenyl-1I-I-pyrrolo[ 1 ,2,3-de lquinoxalin-2( 3H )-one; and 1-( 3-dimethylaminopropyl-5-(p-hydroxyphenyl 6-methyll I-I-pyrrolo[ l ,2,3-de]quinoxalin-2( 3H)-one.

When the compounds (III and V) of this invention are employed as central nervous system depressants they may be administered to warm-blooded animals, e.g. mice, rats, rabbits, dogs, cats, monkeys, etc. alone or in combination with pharmacologically acceptable carriers, the proportion of which is determined by the solubility and chemical nature of the compound, chosen route of administration and standard biological practice. For example, they may be administered orally in the solid form containing such excipients as starch, milk sugar, certain types of clay and so forth. They may also be administered orally in the form of soltuions or they may be injected parenterally. For parenteral administration they may be used in the form of a sterile solution containing other solutes, for example, enough saline or glucose to make the solution isotonic.

The dosage of the present central nervous system depressants will vary with the form of administration and the particular compound chosen. Furthermore, it will vary with the particular subject under treatment. Generally, treatment is initiated with small dosages substantially less than the optimum dose of the compound. Thereafter, the dosage is increased by small inerements until the optimum effect under the circumstances is reached. In general, the compounds of this invention are most desirably administered at a concentration level that will generally afford effective results without causing any harmful or deleterious side effects.

EXAMPLE 1 1-Nitroso-3,4-dihydroquinoxalin-2(3H)-one g., 0.1 13 mole) is stirred in glacial acetic acid (300 ml.) and zinc dust (40 g.) is added in portions while keeping the temperature below C. When all of the zinc has been added the mixture is stirred an additional 20 minutes. Then the reduction mixture is filtered into a 1 liter flask containing propiophenone (15.2 g., 0.1 13 mole), and the zinc cake washed with acetic acid 100 ml.) before it dries. The solution is stirred and slowly heated to reflux until crystals form. If crystals form before reflux, the mixture is refluxed for 10 minutes, cooled to 20 C. in ice, filtered and washed with acetic acid then ethanol, giving light yellow crystals l 1.2 g,, 36%), m.p. 285-288C. (uncorr.) which crystallized from dimethylformamide, give white crystals of 6-methyl-5- phenyl-lH-pyrrolo[1,2,3-de]quinoxalin-2-(3H)-one (10.7 g., m.p. 288 -290C. (uncorr.).

Anal: Calcd for C H N O: C, 77. 4; H. 5.38; N. 10.68.

Found: C. 77. 2; H, 5.31

EXAMPLE II KETONE PRODUCT N'methyl-4-piperidone 7,8 ,9. l 0-tetrahydr0-8-methyl K ETON E a-tetralone butyrophenone cyclododecanone phenyl-Z-propanone ethylacetoacetate benzoylacetonitrile 4-hydroxy4'-methoxybutyrophenone 4-hydroxy-4'-methoxy butyrophenone Z-pentanone alerophenone m-chloropropiophenone o-chloropropiophenone levulinic acid p-benzyloxypropiophenone p-methoxypropiophenone p-chloropropiophenone 7 .S-dihydrol H-benzo[ a ]pyrazino l3.2,1-jk]carbazol-2(3H)-one. m.p. 309-311C.. (23% yield). 6-ethyl-5-phenyl-1H-pyrrolo 1,2.3-de]quinoxalin-2(3H)-one, m.p. 245246C., (54% yield). 7.8.9.1011.12.13.14,15.16- decahydro-1H-cyclododeca[4.5]- pyrr0lo[ l.2.3-de]quinoxalin -2(3H)-one. m.p. 247249C., (56% yield).

[ 1.2.3-de]quinoxalin2(3l-l)one. m.p. 282284C., (51% yield).

2 .3-dihydro-5-methy12-oxo- 1 H- pyrrolo[ l.2.3-de]quinoxaline-6- carboxylic acid, ethyl ester,

m.p. 266.5-267.5C., (15% yield) 2.3dihydro-2-oxo-5-phen ll H- pyrrolo[ 1.2,3-de1quinoxa ine-6- carbonitrile, m.p. 312-313C.. (36% yield). 6-(Z-hydroxyethyl)-5-(p-methoxyphenyl)-lH-pyrrolo[1.2.3-de1- quinoxalin-2( 3H)-one. acetate. m.p. 199201C.. (6% yield). 6-(2hydroxyethyl)-5-(pmethoxyphenyl l H-pyrrolo[ 1,2,3-de1- quinoxalin2(3H)-one. m.p. 231- 233C, (9% yield). 6-ethyl-5-methyl-1H pyrrolo [1.2,3-de]quinoxalin-2(3H)-one, m.p. 2l7-219C., (38% yield). 5-phenyl-6-propyl- 1 H-pyrrolo l l,2,3-de]quinoxalin-2( 3H)-one, m.p. 230230.5+C.. (48% yield). 5-( m-chlorophenyl )-6-methyl 1 1+ pyrrolol l,2,3-de]quinoxalin- 2(3H)-one, m.p. 273276C., (60% yield).

5 o-chlorophenyl )-6-methyl-l H- pyrrolo[ 1.2.3-de ]quinoxalin- 2(3l'l)-one. m.p. 219222C., (28% yield).

2,3-dihydro-5 -methyl2oxo- 1 H- pyrrolo[ l.2,3-de]quinoxaline-6 acetic acid m.p. 286-287C. (decomp.), (28% yield).

-1 l-l-pyrrolo[ 1.2.3-de ]quinoxalin -2(3H)-one, m.p. 270273C.. (52% yield). 5-(p-methoxyphenyl)-6-methyl l H-pyrrolo[ 1.2,3-de1quinoxalin -2(3H)-one, m.p. 278281.5C.. (51% yield). S-(p-chlorophenyl)-6-methyl1H- pyrrolo[ l,2,3,-de]quinoxalin- 2(3H)-one, m.p. 333-336C., (57% yield).

EXAMPLE lll l-benzosuberone cycloheptanone cyclooctanone 4-t-buty1cyclohexanone 3-benzoylpropionic acid cyclopentanone -Nitroso-3,4-dihydroquinoxalin-2( ll-l)-one (0.565 mole) is stirred in glacial acetic acid (1500 ml.) and zinc dust (200 g.) is added in portions while keeping the temperature below 25C. When all of the zinc has been added, the mixture is stirred an additional half hour. Then the reaction mixture is filtered into a five liter flask containing 1,3-diphenylpropanone (0.565 mole), and the zinc cake washed with acetic acid (500 ml.). The reaction solution is stirred and slowly heated to reflux until crystals form. If crystals form before reflux, the mixture is refluxed for 10 minutes, cooled in ice, filtered and washed with acetic acid then ethanol,

giving crystals of 5-benzyl-6-phenyll H-pyrrolo[ l,2,3-de]quinoxalin-2- (3l-l)-one, m.p. 240-242C. (55% yield).

Anal. Calcd for C- -,H,,.N 0: C, 81.63; H. 5. Found: C. 81.46; H, 5.

EXAMPLE IV When the procedure of Examples llll is repeated to react a l-nitroso-3,4-dihydroquinoxalin-2( lH)-one with an appropriate ketone, there is afforded compounds of the following formula:

A H-N w N R R l 3 hydrogen 8-cyano p-tolyl propyl 8-chloro 9-chloro carboxy p-bromophenyl 8-trifluorohydrogen hydrogen carbomethoxy methyl 7-ethoxy S-amino carbamyl p-hydroxyphenyl 9-bromo 8-carboxy p-ethylphenyl hydrogen 8-ethyl hydrogen hydrogen p-methoxyphenyl 8-fluoro 9-sulfamyl hydrogen butyryl 8-nitro 9-phenyl p-iodophenyl hydrogen S-carbamyl 9- hydrogen valeryl methylthio 7-butyl hydrogen hydrogen carbethoxy S-ethylthio 9-iodo phenpropyl hydrogen 8-methoxy 9-methoxy hydrogen dimethylaminoethyl p-chlorophenyl hydrogen hydrogen hydrogen 8-morpholino hydrogen hydrogen Z-pyridyl 9- 9-propoxy hydrogen Z-naphthyl methylsulfonyl hydrogen hydrogen cyano ucetamido S-ethylsulfonyl 9-acetyl hydrogen m-fluorophenyl 7-carbomethoxy 8-benzyl hydrogen naphthyl 8- hydrogen hydrogen Z-furyl dimethylamino R-pyridyl 9-butylthio dimethylaminohydrogen p py hydrogen 9-benzy1oxy hydrogen hydrogen S-carbethoxy 9-p-bromop-butoxyphenyl hydrogen phenyl 7-propionyl hydrogen hydrogen phenethyl S-phenethyl hydrogen hydrogen hydrogen 8-propionamido hydrogen hydrogen carbpropoxy EXAMPLE V l-Nitroso-3,4-dihydroquinoxalin-2( lH)-one (0.226 mole) is stirred in glacial acetic acid (600 ml.) and zinc dust (80g) is added in portions while keeping the temperature below 25C. When all of the zinc has been added, the mixture is stirred an additional half hour. Then the reduction mixture is filtered into a 1 liter flask containing N-ethyl-4-piperidene (0.226 mole), and the zinc cake washed with acetic acid (200 ml.). The reaction mixture is stirred and slowly heated to reflux for ten minutes. Thereafter, the mixture is cooled in ice, filtered and washed with acetic acid then methanol, to afford 8-ethyl-7,8,9, l O-tetrahydrol H- pyrido[ 3 ',4':4,5 ]pyrrolo[ l ,2,3-de]quinoxalin- 2(3H)-one.

Similarly, when the following ketones are reacted with and appropriate l-nitroso-3,4-dihydroquinoxalin- 2( lH)-one, the following products are afforded:

KETONE PRODUCT N-propyl-4-piperidene Continued KETONE PRODUCT l -methy1piperidone 7 .8 .9. l O-tetrahydro-S .B-dimethyl 4-propylpiperidone EXAMPLE VI When the procedures of the prior Examples are repeated to react a l-nitroso-3,4-dihydroquinoxalin- 2(lH)-one with an appropriate ketone, the following compounds are prepared: 6-(3-hydroxypropyl)-8- phenbutyll H-pyrrolo[ l ,2,3-de]quinoxalin-2(3H)-one propionate;

8-benzyl-lH-pyrrolo[ 1,2,3-de]quinoxaline- 8-(2-fury1)-ll-l-pyrrolo[ l ,2,3-de]quinoxalin- 9-diethylamino-lH-pyrrolo[1,2,3-

de]quinoxalin2(3I-l)-one; 8-(2-naphthyl)-1l-l-pyrrolo[1,2,3-

de]quinoxalin2(3H)-one; 7(m-butylphenyl)-1H-pyrrolo[1,2,3-

de]quinoxalin2(3H)-one;

8-(p-methoxyphenyl)- l H-pyrrolo[ 1 ,2,3-

de]quinoxalin2(3H)-one;

8-(p-propoxyphenyl)- l l-l-pyrrolo[ 1,2,3-

de]quinoxalin2(3l-l)-one; 8-phenethoxy-1H-pyrrolo[ l ,2.3-de]quinoxalin- 2(3H)-one;

9-dipropylaminol H-pyrrolo[ l ,2,3-

de]quinoxalin2(3H)-one;

de]quinoxalin2(3l-l)-one;

8(o-iodophenyl)- l l-l-pyrrolo[ 1,2,3-

de]quinoxalin2(3H)-one; and

8-(N-methyl-N-propylamino l H-pyrrolo[ 1 ,2,3-

de]quinoxalin-2(3H)-one.

EXAMPLE VII 6-Ethyl-5-phenyl-1H-pyrrolo[1,2,3-de]quinoxa1ine- 2(3H)-one (8.3 g., 0.03 mole) is added to a mixture of hexane washed 50% sodium hydride (1.52 g., 0.0316 mole) in anhydrous dimethylformamide (50 ml.), and the mixture is stirred at room temperature until all the solids dissolve. A solution of 3-dimethylaminopropy1 chloride (4.02 g.. 0.033 mole) in anhydrous dimethylformamide (5 ml.) is added all at once, and stirred at 90C. for one and a half hours. All of the solvent is removed under vscuum and the residue is dissolved in a mixture of methylene chloride-water. The water is extracted once more with methylene chloride. and the methylene chloride washed with water, saturated salt, and dried with sodium sulfate. Concentration under vacuum, gives a tan solid (10 g.), m.p. 108C. (uncorr.). The solid is crystallized from absolute ethanol, giving white crystals of 6-ethyl-1 3 dimethylaminopropyl)-5-phenyll H-pyrrolo 1 .2,3- de]quinoxalin-2(3H)-one (9.5 g., 88% yield), m.p. 1l4l 16C. (uncorr.).

Anal. Calcd for C ;,H ,;N;.O: C. 76.42; H. Found: C. 76.36; H. 

1. 7,8,9,10-TETRAHYDRO-8-METHYL-1 H-PYRIDOL(3''4'':4,5)PYRROLO(1,2,3-DE)QUINOXALINE-2(3H)-ONE. 